I Built a Secret Door to Trick My Cat

Added: 2026-05-09

[00:00:00]This painting is actually a door and it's hiding the solution to the most frustrating problem in my life. It's so frustrating that I spent a month engineering a solution with woodworking, coding, and robotics. If this doesn't work, I might actually lose it because it is so infuriating.

[00:00:19]When my cat starts meowing for her dinner like 2 hours early, girls, what y'all trying to do?

[00:00:30]POV. It's 3:30 p.m. and you are locked in. When suddenly you feel a claw stab into your leg.

[00:00:36]>> Penny, it's too early.

[00:00:39]>> And that's the first sign that I'm not going to get any peace and quiet until I feed this little monster. And you know, don't get me wrong, I love Penny to the moon and back. She's my day one, my little 8 lb wobbly sidekick. Although, I do think Penny's gaslighting me because she stops meowing the second I turn on the camera. Meow. And honestly, if all I got to eat every day was 58 g of dry kibble, I might also scream at my human to feed me.

[00:01:02]>> Mom, mom, mom, mommy.

[00:01:07]>> So, here we are. Penny always wins this battle. Even if I hold out until her proper dinner time, she thinks she's getting fed because she bothered me, which leads to this vicious feedback loop in my slowly declining mental health, which I just sort of accepted until one day. So, down here next to the giant thing of bulk olive oil, we have this funny little door. Hi, Penny. This is all for you. This is just like a panel.

[00:01:36]I think this is here because there's a garbage disposal under the sink and it's a really deep cabinet. So, the cutout provides easy access for maintenance.

[00:01:43]But once I cleared out a bit of clutter, I realized that there is a ton of space under here.

[00:01:49]>> Man, if I was 9 years old and we were playing hide and seek, I would 100% hide in here. There's so much space in there, dude. Look at this. This is gigantic in here.

[00:02:01]>> Maybe a little small for a full- grown human, but definitely big enough for an 8 lb cat. Are you exploring? I saw you looking in there. Is that your new spot?

[00:02:09]>> And I'm the type of person who sees a weird nook in my house and immediately wants to turn it into a whimsical feature.

[00:02:15]>> Imagine there was just a little secret painting right there that just automatically brought out her food at 4:20 every day. To bring this vision to life, the first thing I had to build was a frame that would hold an extendable platform as well as all the electronics.

[00:02:30]This project was finally going to force me to use microcontrollers, servos, and sensors, which is a skill that I've been excited to unlock. But one skill I'm not unlocking in this project is professional painting. So, while I was building this, I posted an Instagram story to find an artist who could illustrate the painting for The Secret Door. And so many talented artists applied. Thank you to everyone who sent me messages. But unfortunately, I could only choose one. One of the first people to respond was this artist known as Blue Quills. and she makes these amazing illustrations in Procreate. The style is a little different from my original vision, but her art just jumped out at me, especially her use of light, and I felt like she could really capture Penny's cartoon character personality.

[00:03:14]So, I gave her the job and moved on to the next step.

[00:03:17]>> You open packages so emphatically.

[00:03:19]You're like, >> says mushroom on it.

[00:03:23]>> This is not a mushroom. It is a smart automatic cat feeder, which yes, on its own, it could completely solve my problem with Penny. But I want to build a robotic secret painting door. Sue me.

[00:03:35]Don't sue me. Oh, this is the first time Penny has seen an automatic feeder, and I think it blew her mind. Once she realized this thing gives her food, it seems like she was an instant fan. And that's the game plan. Remove the association with me giving her food and transfer that to the robot. Day one with a slow feeder. It is currently 2:28 in the afternoon, a full 2 hours before Penny's dinner time, and she is already meowing for her dinner. But it's still early days. So, while Penny was getting trained up and Blue Quills worked on some sketches, I started work on the moving platform that will bring out the automatic feeder when the painting opens. I'm cutting this on my CNC because I'm using linear guide rails and bearing blocks. So, this will ensure that the two bearing blocks for each guide rail are perfectly aligned and that the guide rails are parallel to each other. But, I've learned that these cheap bearing blocks are never perfect.

[00:04:30]So, I oversized the holes, left the screws loose, and then inserted the linear guide rails, which brings the bearing blocks into perfect alignment.

[00:04:37]And by screwing the blocks down with the guide rails in there, I can lock that alignment in place. And by keeping everything assembled while I screw the guide rails to the frame, I can make sure that the guide rails stay nice and parallel. And there we go. We have an extendable platform ready to be controlled with a linear actuator. Day three of the automatic feeder. And Penny still hasn't realized that it's not me controlling her food anymore. All right.

[00:05:02]So, I'm very excited about this. Not this, but this is to show you why I'm excited. If you've been watching my videos recently, you've probably noticed that I've been using this style of linear actuator for a lot of things.

[00:05:14]These are cheap. They're very strong, but it is extremely slow and it's pretty loud, too. But I just found this. Look at this. You ready? You ready?

[00:05:31]So much faster.

[00:05:32]>> It's also super low profile, so it can easily fit under the platform.

[00:05:36]>> That's good. That'll allow it to not bind up. If this isn't perfectly parallel to these, which it probably isn't. It will self align. The business end of the actuator connects to a bolt that goes through the platform. Super simple setup, but I'm still a relative newbie in these mechanical projects. And when I see something I built move for the first time, it is so exciting.

[00:05:57]>> I love it so much. This is so fun.

[00:06:00]>> Now, this is just a simple two wire linear actuator. To reverse the movement, you have to switch the positive and negative wires. And to do that automatically, all right, here's the setup. So, we got the Arduino connected to an RTC module, which works.

[00:06:14]We're not using it for now. This main test is to test two channels of a 4 channel relay. Those are wired up to the linear actuator power supply and the linear actuator itself in an Hbridgeidge. The idea is that by toggling these on and off, we can control the linear actuator to go in and out.

[00:06:32]Yeah, kind of an underwhelming result considering how much hardware that required, but I guess that's electronics for you. So, while I continued to figure out how to get all this stuff to work together, Blue Quills was preparing four sketches so I could decide on the final painting. One thing I asked her to include was Abby play bowing to Penny, almost like she's a royal subject bowing to her queen. Because, let's be real, Abby might be bigger, but Penny is the alpha. And this was my favorite option.

[00:06:59]So, Blue Quills got to work converting that into a fullcolor illustration while I started experimenting with the UI Make E1. This is an athome fullcolor UV printer, and it's what I'm going to use to print the painting. Now, UI Make is the sponsor of this video, but ever since this machine came out, I've been dying to try it because not only can you use it to create full color images on almost any hard surface, but it can also add 3D texture. My game plan was to use this texture function to make the penny painting look like a real oil painting with brush strokes and depth. While Blue Quills worked on the painting, I wanted to see what this 3D texture feature could do. So, I printed this graphic, which I hired an artist to make a couple years ago commemorating Penny's infamous mountain adventure. Wow, that is incredible. And the auto relief is so cool.

[00:07:48]>> This is pretty sweet. But I think one of the coolest things you can do with the 3D texture is make full-on imitation materials. I'm talking stone, tile, leather. And this really got my gears turning. I started thinking about this boring black platform and how it could be so much more interesting. I mean, this is basically the floor of Penny's kitchen, so why not make it look like a kitchen floor? Woohoo!

[00:08:13]I love this. It's kind of a French beastro vibe, and I feel like it's going to look so cool next to the rich gilded painting. Oh yeah, almost forgot to mention. I got joystick control working, so I can manually position the platform with the Y-axis. I'll also use this for a simple user interface, and the X-axis of the joystick will move this servo, which I'll use to open the painting door. This is my first real electronics project, so every step of this was new and exciting to me, including the need for a box to contain the chaos. And there's a million options for this. I opted to use this free website called Maker Case to generate files for a customsized laser cut box. You just put in your dimensions, download a vector file, and you could throw this directly into a laser cutting software, but I just added a couple cutouts to run the wires.

[00:08:59]There's all sorts of parametric 3D printed electronics enclosures, which are cool and all, but the nice thing about a wooden box is you can just screw the components anywhere. No need to 3D model any exact mounting holes. We're getting there, but it's still looking pretty messy in large part because of these two clumps of wires. These are all of the positive and negative wires for the Arduino, joystick, screen, clock, motors, relay, and these all just need to be joined. So, I picked up some WGO connectors, which are a super easy way to connect a bunch of wires. Penny, it is day like nine of getting you on the automatic feeder. And it is 218.

[00:09:37]It's like 2 hours away from your dinner time. As fun as it was to watch Penny at the automatic feeder, it didn't really seem like this was working. She was still bothering me hours before her dinner time. But hopefully that was all about to change because I had finally figured out all the software problems with the scheduling, or so I thought, and it was time to get this thing installed. You probably noticed it's really dark down here, so I started by putting up a USB powered spotlight, which will highlight the painting. And Blue Quills was almost done. I was so excited to get that printed. But for now, I was in for a couple hours of crawling around under the sink to get the frame fully secured.

[00:10:13]>> Why do I keep building projects in confined space and the garage is calling it?

[00:10:17]>> I got to say, huge props to plumbers. I find this experience so frustrating when you're half under a sink, tied in a knot, trying to use a drill.

[00:10:25]>> I'm really frustrated right now because one of the linear actuator wires was pulled out when I was moving stuff around and it uses the tiniest wires. I have to get it back into the relay in this tiny confined under space.

[00:10:40]>> Though it was hilarious watching Penny explore every corner of the cabinet while I was working in there. And I think in the end, her curiosity got me through this extremely frustrating hour.

[00:10:50]>> Okay, we got it all reconnected.

[00:10:58]Why do I keep doing all these projects in confined spaces? So, it felt like a breath of fresh air to be back out in the shop to build the next part of this project. When I first set up the automatic feeder in that little doorway, I noticed it was almost too tall for Penny. She would even take food down to the ground. And with the platform I just installed, it's even taller. Penny needs a little stool. And this was a great opportunity to take this little nook to the next level and really create a miniature scene. There's this great fabric store here in Vancouver. Shout out to Fabrictime. They have literally every fabric you could want. That's where I found this, which looks like the carpet you would see in a royal throne room. And after a few too many janky upholstery projects, guess who finally learned how to wrap corners correctly.

[00:11:41]>> Woohoo! That's clean. Look at my corners. For the base, I cut a piece of 3/4in plywood a bit smaller than the top. And I have a bunch of scrap sapili from my tiny library. So, I cut this to size and glued it to the plywood. I didn't want any nails visible, so I used the old trick where Penny just me Penny, stop meowing. Penny's literally meowing for her dinner as I'm trying to record this voice over. I used the trick where you alternate dots of superglue and wood glue. And the super glue pretty much acts as clamps while the wood glue dries. Couple coats of Danish oil, then I can just screw the plywood directly to the top. And we got ourselves a throne fit for a queen. Now, I know this still looks really janky, but that's going to change real soon because Blue Quills had just finished the painting. So, I made a quick test print on a small piece of acrylic.

[00:12:27]>> Oh.

[00:12:30]Oh my god, it's amazing. Oh my gosh, it's everything I ever dreamed of.

[00:12:38]>> Well, that's all the encouragement I need to make the fulls size painting, which I'm printing on a big piece of acrylic. This is 12x4 in, and it easily fits on the E1 print bed, but you can actually print stuff up to 10 m long with the roll to film attachment. I'm using the automatic texture creation, which works by building up layers of white UV ink. And the machine actually ran out of white ink partway through this 8-hour print. But no problem, it just automatically stopped, sent a notification to my phone, and I could swap out the cartridge and just hit resume.

[00:13:16]Oh, wow.

[00:13:19]Yeah, dude. That is so cool.

[00:13:25]>> Oh my god, it's amazing.

[00:13:29]>> But to turn this into a secret door, I needed a next level picture frame. And I've made a few frames, but I'm not very good at it. The only ones I've made are simple and modern, and that is definitely not the vibe here. I want it to look opulent, royal, and gilded. So, I went to a local framing store where I found this frame, which was perfect. But the shopkeeper said it would take 2 weeks to make because they have to order the stock on demand from Italy, and that was just not going to work. So, I went to a thrift store. This is a classic hack to find cheap but relatively highquality frames. Not feeling too optimistic. You look all really small. I mean, I was willing to pay for a nice frame, but it's so frustrating when you try to support a local business and it's just impossible. Anyways, apparently I accidentally made the penny painting kind of a standard size. I found two frames that could work, but when I brought them home, they just felt cheap and corny. My mind kept going back to that perfect frame from the framing store, and I was not going to compromise on this. This was going to make or break the entire aesthetic. So, I opened up Amazon just to just to see, you know, maybe there'd be something that was close to that cool frame from the framing store. And what do you know?

[00:14:43]What y'all trying to do?

[00:14:46]>> All right, the question, does this look the same in real life as it did in the listing? Because in the listing, it looked identical to the fancy Italian frame, which probably means it's a knockoff, which I don't really feel good about. But hey, when you need something fast, Amazon is great. So, as long as this is high quality and looks good.

[00:15:06]>> Oh, yeah.

[00:15:08]>> Yeah, that looks pretty identical to me.

[00:15:10]And honestly, it feels just as high quality as the frame in the store. But the only one in stock was too big. So, it was time to put my mediocre picture frame building skills to the test.

[00:15:25]Now, on paper, making picture frames shouldn't be that hard. It's just four mitered corners attached together. But, it's one of those crafts that really benefits from jigs and a dialed in process, which is why frame shops are a thing. So, I'm just kind of winging it here, doing what makes sense to me. I put a domino in each end. And because I don't have the right kind of clamps, I just use the old superglue clamp method, dude. Check it out. It's not perfect, but I'm not even going to zoom in on the imperfections because it doesn't matter.

[00:16:07]Who cares about the imperfections? This is sick. I am so happy I held out for the perfect picture frame. You know, sometimes compromise is good, but sometimes the details just really make all the difference.

[00:16:18]>> Wow.

[00:16:21]So regal.

[00:16:22]So expensive.

[00:16:24]>> And an expensive looking painting is fine, but an expensive looking painting that's actually a robotic secret door is awesome. And the door part was pretty easy, but the robotic part, I've never made anything like this. So, I just started by laser cutting this simple arm just to get a sense of how the servo would work as a door opener.

[00:16:44]That's a bad orientation.

[00:16:46]>> Pro tip, if you're cutting something long out of solid wood, make sure you orient the wood grain with the long axis. much better.

[00:17:00]My first test was promising, but the door didn't open nearly enough. So, I started by making a longer arm, and this helped, but I wanted it to open even further. And I realized that I could get a bigger range of motion if I just brought the servo further out. Penny, get out of here.

[00:17:18]So, I designed a new 3D printed mounting bracket, and combined with the longer arm, this worked great. The door opens so much further, which Penny seemed excited to see. And this guy will allow the servo to close the door as well as open it.

[00:17:32]>> Penny, can you please get out of here?

[00:17:33]>> I also considered using a spring that would always pull the door closed, but that would put constant load on the servo, which doesn't really seem ideal.

[00:17:40]>> Okay, here we go. First test. So, I opted for this strategy, which I could have designed fully on the computer, but it's so much more fun to test prototypes in the real world, iterate, and redesign, especially when laser cutters allow you to cut new parts in like 2 minutes. So, while I was trying to maximize the servo's range of motion, I actually realized that I can rotate it to a full 180°. I was limiting it to 120 for no reason at all. So, I added this menu screen that allows me to adjust the minimum and maximum angles as well as the servo speed so I can get that door opening perfectly dialed in. Now, at this point, Penny was extremely curious, so I thought I would set up a test feeding to start showing her what this was all for and to see if my code was finally bug-free.

[00:18:23]>> All right, in about 30 seconds, it should go off.

[00:18:28]>> Should being the operative word >> any moment now. Any moment. It's not going for some reason. Why isn't it going? What the heck?

[00:18:37]>> But the feeder doesn't care if the door doesn't open. So, at Penny's scheduled dinner time.

[00:18:43]>> Sorry, Penny. I don't know why it didn't go off. I'll have to go open it manually from the back.

[00:18:47]>> But Penny heard the automatic feeder go off, so she was getting to her dinner with or without my help. And she actually opened the door before I could get to the control box. This actually turned out to be a pretty simple software bug. I had a line of code that stopped the program from running if it had already run that day. and it was misinterpreting my tests as scheduled feedings. Does the debugging ever really end?

[00:19:10]Okay, I think I've gotten all the bugs figured out. This is set to trigger at 8:05.

[00:19:18]And finally, it worked. Let's go. Let's go.

[00:19:23]This is like the freak. Yeah, this is the first time I've actually seen it work automatically from this side cuz I've been like putting around in the back. It's delaying 10 seconds.

[00:19:35]Yeah. And then only after it retracts, it should now close nice and slowly.

[00:19:45]Oh, it's so cool. But not as cool as using the secret painting door to actually finally automatically feed Penny dinner.

[00:19:56]So, on top of this being the very first secret painting dinner service, Eden hadn't yet seen this thing in action, and I was so excited to show her. But I don't think she was quite prepared for how fun this thing is. Penny seemed to remember, though, because a minute before dinner time Oh, she's trying to she's trying to open the painting on her own. She knows it's behind that.

[00:20:18]>> All right. Any moment now.

[00:20:20]>> Is the painting supposed to open?

[00:20:22]>> Oh, there we go.

[00:20:28]There we go.

[00:20:37]>> Let's set this fire in your eyes to the moon.

[00:20:53]what y'all trying to do.

[00:20:55]>> Now, as excited as Penny is to absolutely house kibble when the feeder goes off, after that initial rush, she likes to have a nice long leisurely dinner. So, I set the program so everything stays extended for 1 hour, after which it retracts and it's ready for the next day.

[00:21:11]So, 4 weeks ago, I embarked on this project because Penny was driving me crazy. But I never expected that the month I spent sketching, building, and debugging with Penny crawling all over me. I never expected that it would have given me this new appreciation for how she approaches the world with this pure curiosity. Penny sees something new and goes right for it with no fear or self-consciousness. And it's honestly so inspiring. It's something that I need more of in my life.

[00:21:43]But you are probably wondering, did this work? Did this robotic secret painting door actually train Penny to stop bothering me for her dinner?

[00:21:58]>> What the?

[00:22:02]>> Let's just say it's a slow training process.

[00:22:05]>> We have a brand new top patron this week. So, special thank you to Amelia K, Sawyer, Paige Art, and my mom, Kathy Curt. Love you, Mom.